ATP players are seeking to roughly double by 2018 the prize money paid out by the circuit’s top nine tournaments, but owners of those events have responded with a far lower proposed increase, according to sources familiar with the discussions.

The tournaments, known as the Masters 1000 events and which include four tournaments in North America, are set to pay out more than $36 million to ATP players this year.

“Players are on one side, and tournaments are on the other,” said Chris Kermode, the ATP’s president, who declined to provide details on proposals made by the two sides.

The proposals were first put on the table in London at tour board meetings shortly before Wimbledon and included a third proposal offered by Kermode, which he described as being in between the other offers.

A source close to the tournaments side criticized the players’ proposal as being disconnected from economic reality and said the tournaments would help singles players by shifting the percentage of tournament prize money paid to them from 80 percent to 87 percent. The remainder falls to doubles players.

The tournaments never fully supported the push by Kermode’s predecessor, the late Brad Drewett, to pressure the four Grand Slam tournaments to increase their purses. The four Slams did agree to dramatic increases, but as the 1000s worried, that left them paling in comparison and next in line for the players.

For example, the U.S. Open Tennis Championships last week announced prize money would hit $38.3 million this summer, with half of that ($19.15 million) going to ATP players. By comparison, the top purse for men of the 1000s is the BNP Paribas Open in Indian Wells, Calif, which awarded $5.24 million in March. Six of the nine 1000s are below $4 million.

Kermode, who began as ATP president this year, said he would not cast a tie-breaking vote as the seventh member of the ATP board on the 1000s prize money controversy. There are three player representatives and three tournament reps. “This has to be done by consensus,” he said.

He added that there will be multiple meetings through the U.S. Open, with a final decision expected by November.

Were a deal not to be reached, the ATP’s contract with the nine tournaments would expire, and the 1000s would be free to set their own prize money. It’s unclear if the world’s top players would still be required to play the events if there is not an overarching agreement with the ATP.